The Most Neglected Topic in Today’s Dry Eye Conversation: Nighttime Dry Eye
Most people don’t think about their eye health when they think about sleep. Probably because for most of us it’s the only time of the day that we don’t use our eyes. But, for a surprising number of adults, nighttime might be the time of day that their eyes need the most help.
At Eye Eco we are plugged in to the dry eye conversation. One thing that we don’t think gets near enough attention is Nighttime Dry Eye.
What Causes Nighttime Dry Eye?
There are several causes of nighttime dry eye including Nocturnal Lagophthalmos, Compromised Lid Seal, Sleep Apnea, Floppy Eye and Aqueous Deficient Dry Eye.
Nocturnal Lagophthalmos occurs when the eyelid does not close all the way during sleep. It’s easy to see how slightly open eyes can lead to dry eye just because of evaporation. But, impartial lid closure can also prevent natural tears from spreading properly. Diagnosis of this condition is important since Lagophthalmos patients are also more likely to experience recurrent corneal erosions.
Compromised Lid Seal was first reported in 2015, and in a recent study was found to affect 79% of all dry eye patients. Compromised Lid Seal occurs when the upper and lower lids do not create a perfect seal. Perhaps the lower lid is a bit thicker that the upper lid and so sticks out farther, similar to an underbite.
Sleep Apnea is a condition in which breathing stops and starts throughout sleep. It can lead to nighttime dry eye in a couple different ways. First, sleep apnea leads to a lack of oxygenation of the optic nerve head during sleep. Second, a common treatment for sleep apnea is the use of a CPAP (continuous positive airway pressure) mask that covers the nose and mouth. The mask is very effective for treating sleep apnea, but often does not create a perfect seal. If the air leaks are near the eyes, then dry eye is a likely result.
Floppy Eye Syndrome is more rare than the other causes we mentioned. It occurs when there is extensive lid laxity. For some, the eyelids can “flip over” during sleep from rubbing against the pillow. It can lead to tear film abnormality and dry eyes.
Aqueous Deficient Dry Eye was long thought to be the leading cause of dry eye, and although that has been debunked – Meibomian Gland Dysfunction is now considered the leading cause of dry eye – there are still millions of people affected. Aqueous deficient dry eye is caused by decreased tear production.
How many people experience nighttime dry eye?
Let’s take a look at the numbers:
- Lagophthalmos can be found in anywhere from 4% all the way up to 20% of the population1
- Compromised Lid Seal is found in 79% of all dry eye patients2(14% of people are dry eye patients3)
- Research suggests that sleep apnea affects 22 million adults in the United States4
- Aqueous Deficient Dry Eye occurs in Sjögren’s Patients of which there are over 4 million in the United States5
At least 27 million adults in the United States have a cause that can lead to nighttime dry eye. (Learn how we got this number.)
At most 118+ million adults in the United States have a cause that can lead to nighttime dry eye. (Learn how we got this number.)
Since these conditions can overlap the answer to how many people have nighttime dry eye is likely somewhere between those two numbers. Which means that for a surprising number of adults, nighttime is probably the time of day that their eyes need the most help.
Helping Nighttime Dry Eye Patients
If your patients experience Nighttime Dry Eye there is an easy fix. Eye Eco offers a range of nighttime masks that protect eyes from the environment, or air leaks from a CPAP mask, and hold in moisture to promote better sleep and eye health.Learn More about Eyeseals™
Stay tuned! Next week we will be sharing a pro tip: One Amazingly Simple Way To Diagnose Microlagophthalmos.
1. Tsai SH, Yeh SI, Chen LJ, et al. Noctural Lagophthalmos. Int J Gerontol. 2009 Jun;3(2):89-95.
2. Donald R Korb, Caroline A Blackie, Amy C. Nau; Prevalence of Compromised Lid Seal in Symptomatic Refractory Dry Eye Patients and Asymptomatic Patients. Invest. Ophthalmol. Vis. Sci. 2017;58(8):2696.
3. G. Foulks, M. Lemp, J. Jester, J. Sutphin, J. Murube, and G. Novack, “Report of the international dry eye workshop,” Ocul. Surf. 5, 65–203 (2007).
4. Sleep apnea. American Sleep Apnea Association website. www.sleepapnea.org/i-am-a-health-care-professional.html. Accessed September 19, 2018.
5. Sjögren’s Fact Sheet. Sjögren’s Syndrome Foundation. https://cdn2.hubspot.net/hubfs/147789/2018%20World%20Sjogrens%20fact%20sheet.pdf Accessed September 19, 2018